A Class of Inertial Measurement Units for Low-Noise Angular Velocity Estimation

An Inertial Measurement Unit (IMU) architecture estimating angular velocity is introduced. It expands the concept of multi-accelerometers gyroscope-free IMUs (GF-IMUs), taking advantage of their excellent noise performance and resolving their inability to compensate for accelerometers' bias and their requirement for specific accelerometers placement, which makes GF-IMUs inappropriate for real world applications. It does so by embedding the accelerometers in a low-bandwidth closed-loop configuration with a three-axis gyroscope and by addressing the complete non-linear dynamics. Extensive theoretical analysis provides a complete framework for designing low-noise IMUs including sufficient stability criteria for the non-linear system's dynamics. Simulation and experimental results support the theoretical analysis and indicate that even a minimal system using the proposed architecture can outperform the gyroscope in noise performance by at most 15dB in some frequency range.